The present invention is generally in the field of pharmaceutical compositions, and specifically relates to compositions that are designed to reduce the potential for improper administration of medications and their use in a non-indicated or non-prescribed manner. The present invention can comprise any drug, especially medications that are subject to abuse. More specifically, it pertains to pain medications, medications to reduce or eliminate anxiety attack (psychotherapeutic drugs), stimulants and sleeping pills. With these general type drugs there is the potential of abuse that may result in drug overdose, addiction, suboptimal efficacy, and/or death.
In particular, the present invention relates to an abuse resistant composition (for, e.g., pain medication, anxiety attack medication, sleeping medication or stimulants), having, but not limited to, a diffusion layer and a barrier layer; use of such a composition in a dosage form to treat diseases or conditions; and a method of making an abuse deterrent composition having a diffusion layer and a barrier layer. In some embodiments, the composition also comprises an expansion layer.
Opioid agonists are substances that act by attaching to specific proteins called opioid receptors, which are found in the brain, spinal cord, and gastrointestinal tract. When these drugs attach to certain opioid receptors in the brain and spinal cord they can effectively block the transmission of pain messages to the brain. Opioid analgesics such as oxycodone, morphine, oxymorphone, hydrocodone and hydromorphone are successful and therapeutically useful pain medications. Unfortunately, they also pose a severe threat for willful abuse due to their ability to alter mood and/or cause a sense of euphoria (a “high”). Currently available sustained release formulations of such drugs, which contain a relatively large amount of drug substance meant to be released from the formulation over an extended time period, are particularly attractive to abusers since the sustained release action can be destroyed by crushing or grinding the formulation. The resulting material (i.e., the crushed formulation) can no longer control the release of drug. Depending on the drug substance, abusers can then (1) snort the material, (2) swallow the material or (3) dissolve the material in water or alcohol and subsequently inject it intravenously. The dose of drug contained in the formulation is thus absorbed immediately through the nasal or GI mucosa (for snorting or swallowing, respectively) or is administered in a bolus to the systemic circulation (for IV injection).
These abuse methods result in the rapid bioavailability of relatively high doses of drug contained in a single tablet or capsule, giving the abuser a “high.” The sense of euphoria, or “high,” is highly correlated with the peak serum concentration of the drug substance (Cmax). Although such a high serum concentration can be obtained from taking several immediate release or sustained release tablets at once, abusers are deterred from doing so because multiple tablets are harder to come by and, may be more importantly, the very high dose associated with taking several tablets at once is associated with an severely increased risk of overdose (typically a function of high serum levels of the drug substance over prolonged periods of time; resulting in a high area under the curve: the integral of the serum concentration over time; also known by the acronym “AUC”). In order to reduce the risk of overdose, the typical abuser will prefer to obtain a high peak serum concentration from a single tablet or capsule. In the scientific terminology of a pharmacologist, the typical abuser appears to maximize Cmax while minimizing AUC, or alternatively, to maximize the Cmax/AUC ratio.
In some cases, abusers consume alcohol with immediate and/or extended release formulations to reach a “high” more quickly. Abusers sometimes place the formulation in water or alcohol, in order to extract the drug in an accelerated fashion. The coadministration of these liquids is known to sometimes decrease the time after drug administration in which the peak plasma concentration and Cmax are reached. Sometimes abusers place the formulation into other solvents such as freon, methylene chloride, ethanol, and acetone, in order to extract the drug, which can then be injected. Another technique used by abusers to extract drug from a dosage form such as a tablet is wiping the coating off of the tablet, crushing the tablet into a fine powder, placing the powder into sterile water, and then drawing the liquid into a syringe. In addition, the dosage form can be generally physically compromised by crushing, grinding, and chewing.
Since relatively simple methods (crushing, grinding, chewing and/or dissolution in water or alcohol) can be used to transform a single extended release tablet or capsule formulation into an abusable form, these conventional dosage forms provide virtually no deterrent to a potential abuser.
The FDA recently strengthened the warnings and precautions sections in the labeling of OXYCONTIN® (oxycodone HCl controlled-release) Tablets, a narcotic drug approved for the treatment of moderate to severe pain, because of continuing reports of abuse and diversion. OXYCONTIN® contains oxycodone HCl (available in 10, 20, 40, 80, and 160 mg strengths), an opioid agonist with an addiction potential similar to that of morphine. OXYCONTIN® is supplied in a controlled-release dosage form and is intended to provide up to 12 hours of relief from moderate to severe pain. The FDA warning specifically states that the tablet must be taken whole and only by mouth. When the tablet is chewed or crushed and its contents are swallowed, snorted into the nostrils or dissolved and subsequently injected intravenously, the controlled release mechanism is destroyed and a dangerous dose of oxycodone becomes bioavailable, which is potentially lethal to users of this product, in particular first time users.
In recent years, there have been numerous reports of oxycodone diversion and abuse in several states. For example, DEA's Office of Diversion Control reported 700 OXYCONTIN® thefts in the U.S. between January 2000 and June 2001. Some of these reported cases have been associated with serious consequences, including death.
Oxycodone is a controlled substance in Schedule II of the Controlled Substances Act (CSA), which is administered by the Drug Enforcement Administration (DEA). Despite the fact that Schedule II provides the maximum amount of control possible under the CSA for approved drug products, in practice it is difficult for law enforcement agencies to control the diversion or misuse of legitimate prescriptions. Although abuse, misuse, and diversion are potential problems for all opioids, including oxycodone, opioids are a very important part of the medical armamentarium for the management of pain when used appropriately under the careful supervision of a physician. Currently available formulations for such drugs are designed for oral administration but do not include mechanisms to prevent or retard improper methods of administration such as chewing, injection and snorting. This represents a serious problem given the large number of legitimate prescriptions written in the U.S.; for example, the medical use of opioids within the U.S. increased 400% from 1996 to 2000.
The problems with abuse are significant and longstanding, and efforts to design new abuse resistant or abuse deterrent formulations have been largely unsuccessful. U.S. Pat. No. 3,980,766 describes the incorporation of an ingestible solid which causes a rapid increase in viscosity (gelling) upon concentration of an aqueous solution thereof. U.S. Pat. No. 4,070,494 describes the incorporation of a non-toxic, water gelable material in an amount sufficient to render the drug resistant to aqueous extraction, thus retarding the release of the drug substance. U.S. Pat. No. 6,309,668 describes a tablet for oral administration containing two or more layers comprising one or more drugs and one or more gelling agents within separate layers of the tablet. The examples in this patent all describe conventional immediate release formulations and the resulting tablets form a gel when combined with the volume of water necessary to dissolve the drug; this formulation thus reduces the extractability of the drug from the tablet. It should be noted that although these compositions may preclude abuse by injections, this approach would fail to prevent abuse by crushing and swallowing or snorting the formulation, which are commonly reported methods of abuse associated with OXYCONTIN®.
U.S. Pat. Nos. 6,277,384, 6,375,957 and 6,475,494 describe oral dosage forms including a combination of an orally active opioid agonist and an orally active opioid antagonist in a ratio that, when delivered orally, is analgesically effective but that is aversive in a physically dependent subject. While such a formulation may be successful in deterring abuse, it also has the potential to produce adverse effects in legitimate patients.
U.S. Patent Application Publication No. 2007/0066537 discloses an abuse resistant opioid wherein the opioid is bound to niacin, biotin or peptide.
U.S. Patent Application Publication No. 2006/0104909 discloses a pharmaceutical composition comprising an opioid and a tamper-resistant matrix comprising one or more tenacious cross-linked polymers that are capable of bonding with the opioid such that the opioid is substantially incapable of immediate release from the polymer. A further preferred aspect uses a water insoluble matrix material comprising a pH insensitive material such as ethylcellulose, cellulose acetate, vinyl acetate/vinyl chloride copolymers, acrylate/methacrylate copolymers, polyethylene oxide, hydroxypropyl methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, triglycerides, hydrogenated vegetable oils, triglyceride polyalkoxyalkylesters, fats, waxes and water insoluble partially-degraded proteins. The surface coating material comprises a hydrophobic polymer such as a pharmaceutically acceptable acrylic polymer such as acrylic acid and methacrylic acid copolymers, methyl methacrylate copolymers, ethoxyethyl methacrylates, cyanoethyl methacrylate, aminoalkyl methacrylate copolymer, poly(acrylic acid), polymethacrylic acid, methacrylic acid alkylamide copolymer, poly(methyl methacrylate), poly(methacrylic acid anhydride), methyl methacrylate, polymethacrylate, polyacrylamide and glycidyl methacrylate copolymers. In certain preferred embodiments, the acrylic polymer is comprised of one or more ammonio methacrylate copolymers. Ammonio methacrylate copolymers are well known in the art, and are described in NF XVII as fully polymerized copolymers of acrylic and methacrylic acid esters with a low content of quaternary ammonium groups.
U.S. Patent Application Publication No. 2005/0281748 discloses an opioid bound to a lipid or fatty acid to produce an abuse resistant drug.
It is an object of the present invention to provide a pharmaceutical composition that significantly reduces the potential for improper administration or use of drugs but which, when administered as directed, is capable of delivering a therapeutically effective dose. In particular, the present invention addresses the need for a drug product which, compared to conventional formulations, decreases the intensity, quality, frequency and rate of occurrence of the “euphoria” effect which can occur with improper administration.